Earlier in his Starfleet career, Eggleton had worked as a medical officer in various deep-space assignments, but had tired of the many problems that could arise with dealing with different alien cultures and the "personalities" of many of his colleagues. In 2258, Eggleton accepted the offer of becoming surgeon general at Starfleet Medical on Earth, where the most contentious thing he had to deal with on a daily basis was a "cranky microbe".